Re-surfacing tool



Nov. 22, 1966 J. 1'. SIMMONS 3,285,552

RE-SURFACING TOOL Filed Nov. 27, 1964 INVENTOR JESSE T. SIMMONS ,9BY

United States Patent 3,28,552 RESURFACING TOOL Jesse T. Simmons, 601 E. Main St., Chattanooga, Tenn. Filed Nov. 27, 1964, Ser. No. 414,160. 4 Claims. (Cl. 772) This invention is concerned with a boring tool, and especially with a tool for re-surfacing the face of a shoulder in a cylinder head forming the seating surface for a sealing gasket.

In certain types of internal combustion engines, the cylinders are made separate from the crank case and have one end fitted into openings in the crank case. The cylinders are closed at the other end by a cylinderhead casting, often made of aluminum, and provided with round openings receiving the ends of the cylinders and forming the combustion chambers for the cylinders. The ends of the cylinders are sealed in the combustion chambers by a sealing gasket placed between the end of each cylinder and an annular shoulder formed in the Wall of each combustion chamber. One cylinder head usually accommodates two or more cylinders, and often the cylinders are arranged in two groups with one cylinderhead for each group.

During operation of the engine it is a common experience that one or more gaps will be burned into the gasket which will damage the gasket seating surface in the cylinder head which is formed of relatively soft metal. If the burning of the gasket seat is severe, the entire cylinder-head must be replaced, but it is often possible to renew the seating surface by a re-surfacing or boring operation. By the present invention the gasket seat in the cylinder head may be re-surfaced by hand operation of a relatively simple tool.

A suitable embodiment of my tool is illustrated in the accompanying drawing in which FIGURE 1 shows the tool in side elevation and in operative position for re-surfacing the gasket seat in one combustion chamber of a cylinder head which is shown in section in an inverted position.

FIGURE 2 is a top or plan view of the tool shown in FIGURE 1.

In FIGURE 1, the inverted cylinder head I is formed of cast metal and has two or more combustion chamber recesses 2 formed in the upper fiat face thereof. Each combustion recess is counter-bored at 2a to receive the end of a cylinder, not shown, and to form an annular shoulder 2b which provides a seating surface for a sealing gasket 3 which surrounds the combustion recess 2. The cylinder head is provided with cooling fins 1a surrounding the combustion chamber, and a tapped spark plug opening 1b for each combustion chamber. The exhaust and intake ports formed in the cylinder head are conventional and have not been illustrated, but it will be understood that the sectional view of the cylinder-head in FIGURE 1 is shown along a cutting plane passing between the inlet and exhaust ports of one chamber 2 and at right angles to the length of the cylinder head.

My boring tool is shown in operative position in FIGURE 1, but it will be understood that the gasket 3 will have been removed before the tool is operated.

The tool is formed of a flat circular body 4 of hard metal, such as steel, and has a circular plug portion 4a of an outside diameter to fit closely within the counterbore 2a but to allow free turning of the plug portion within the counter-bore. The tool body 4 also has a radical flange portion 412 at the upper end of the plug 3,286,552 Patented Nov. 22, 1966 "ice portion and extending radially beyond the counter-bore 2a.

In operation of the tool the flange 4b is seated on the face of the cylinder-head 1 surrounding the bore 2a and maintains the lower end of plug portion 4a near but spaced above the gasket-seating shoulder 2b.

The cutting bit 5 of the tool is formed of a length of square-bar stock of hardened tool steel, and is located within a slot 5a formed vertically in the outer surface of the plug portion 4a. The slot 5a is extended upwardly through the upper part of body 4 in the form of a square hole 5b through which the bit 5 may be introduced and adjusted vertically. The lower end of the bit is hardened and shaped to provide a cutting edge which extends entirely across the shoulder 2b forming the seat for gasket 3. The depth of cut is adjusted by adjusting the vertical position of the bit in the tool body. The cutting bit is held in adjusted position by a clamping screw 6 which is threaded into the flange portion 412 opposite the bit so that the inner end of the screw engages the bit and clamps it against the wall of the opening 5b. The screw 6 is provided at its outer end with an operating handle or lever 7.

For the purpose of adjusting the bit for a definite depth of cut, a thin metal strip 8 is provided to act as a thickness shim or gauge. The shim has a thickness equal to the desired maximum depth of cut. The shim is flat at one end and curled up at the other end for convenient handling, as shown in FIG. 1. In use, the fiat end of the shim is inserted between the flange 4b and the cylinder head 1 in the manner shown in FIG. 1 and the tool is rotated until the bit 5 is opposite the end of the shim. The screw 6 is then loosened and the bit 5 is pressed down until its cutting edge engages the surface of shoulder 2b and the screw 6 is then tightened to clamp the bit in proper position. The shim 8 is then removed, and resurfacing of the shoulder 2b is accomplished by rotating the tool in any desired manner. This may be done manually by providing a suitable operating handle, such as that shown in the drawing and formed of a verticle stem or post 9 mounted at the center of the body 4 and having a double-ended handlebar 10 secured to its upper end.

For convenience of storage when not in use, the shim or gauge 8 may be clamped to the body 2 of the tool by slipping the fiat end under a thin metal strap 11 fastened to the upper face of the tool body, as shown in FIG. 2.

I claim:

1. A tool for re-surfacing the gasket-seating shoulder Within the combustion chamber bore of a cylinder head comprising, a flat circular body having a circular plug portion of a diameter to fit closely within said bore and for free-turning within said bore, said body having an annular flange at the upper portion thereof extending radially beyond sail plug portion and being seated on the face of said cylinder-head surrounding said bore during re-surfacing operation, said body and plug and flange being formed as an integral unit, said flange holding said plug portion near but spaced from said shoulder, said body having a hole extending through the body parallel with the axis of the body'and opening through the plug portion thereof at the gasket-seating surface of said shoulder, a cutting bit located within said hole and having a cutting edge to engage the entire width of the gasket-seating surface of said shoulder, said bit being adjustable in position along the length of said hole, and releasable clamping means for holding said bit in adjusted position within said hole.

2. A tool according to claim 1 and including a thin shim to be inserted between said flange and its seating surface on said cylinder-head during adjustment of said bit, to fix the depth of cut when the shim is removed.

3. A re-surfacing tool according to claim 1, including an operating handle for turning the tool comprising a stem secured to said body at the center thereof, and a double-ended handle-bar secured to the end of said stem.

4. A tool according to claim 1 wherein the opening through the plug portion constitutes a slot in registry with the vertical hole in said body.

4 References Cited by the Examiner UNITED STATES PATENTS 820,550 5/1906 Cartier 9012.5 967,532 8/1910 Lockett 9012.5

FOREIGN PATENTS 6,744 5/ 1890 Great Britain.

WILLIAM W. DYER, JR., Primary Examiner. G. A. DOST, Assistant Examiner. 

1. A TOOL FOR RE-SURFACING THE GASKET-SEATING SHOULDER WITHIN THE COMBUSTION CHAMBER BORE OF A CYLINDER HEAD COMPRISING, A FLAT CIRCULAR BODY HAVING A CIRCULAR PLUG PORTION OF A DIAMETER TO FIT CLOSELY WITHIN SAID BORE AND FOR FREE-TURNING WITHIN SAID BORE, SAID BODY HAVING AN ANNULAR FLANGE AT THE UPPER PORTION THEREOF EXTENDING RADIALLY BEYOND SAIL PLUG PORTION AND BEING SEATED ON THE FACE OF SAID CYLINDER-HEAD SURROUNDING SAID BORE DURING RE-SURFACING OPERATION, SAID BODY AND PLUG AND FLANGE BEING FORMED AS AN INTEGRAL UNIT, SAID FLANGE HOLDING SAID PLUG PORTION NEAR BUT SPACED FROM SAID SHOULDER, SAID BODY HAVING A HOLE EXTENDING THROUGH THE BODY PARALLEL WITH THE AXIS OF THE BODY AND OPENING THROUGH THE PLUG PORTION THEREOF AT THE GASKET-SEATING SURFACE OF SAID SHOULDER, A CUTTING BIT LOCATED WITHIN SAID HOLE AND HAVING A CUTTING EDGE TO ENGAGE THE ENTIRE WIDTH OF THE GASKET-SEATING SURFACE OF SAID SHOULDER, SAID BIT BEING ADJUSTABLE IN POSITION ALONG THE LENGTH OF SAID HOLE, AND RELEASABLE CLAMPING MEANS FOR HOLDING SAID BIT IN ADJUSTED POSITION WITHIN SAID HOLE. 